Commands by op4 (7)

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Add a line to a file using sudo
This is the solution to the common mistake made by sudo newbies, since $ sudo echo "foo bar" >> /path/to/some/file does NOT add to the file as root. Alternatively, $ sudo echo "foo bar" > /path/to/some/file should be replaced by $ echo "foo bar" | sudo tee /path/to/some/file And you can add a >/dev/null in the end if you're not interested in the tee stdout : $ echo "foo bar" | sudo tee -a /path/to/some/file >/dev/null

Getting the last argument from the previous command

grep apache access.log and list IP's by hits and date - sorted

list block devices
Shows all block devices in a tree with descruptions of what they are.

File rotation without rename command
Rotates log files with "gz"-extension in a directory for 7 days and enumerates the number in file name. i.e.: logfile.1.gz > logfile.2.gz I needed this line due to the limitations on AIX Unix systems which do not ship with the rename command.

check open ports without netstat or lsof

Restart openssh-server on your Synology NAS from commandline.
The correct way to restart openssh-server on your synology nas.

Check if a string is into a variable
Returns true (0) if the string is into $var, or false (1) if not.

continuously check size of files or directories
very handy if you copy or download a/some file(s) and want to know how big it is at the moment

Rename file to same name plus datestamp of last modification.
FILENAME=nohup.out mv -iv $FILENAME{,.$(stat -c %Y $FILENAME)} does it help ?


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